This is the Light up tee's that everybody's talking about - the sound activated equalizer light up tee's with adjustable sensitivity ! Walk into a disco, bar or nightclub or just any party with this shirt on and the shirt equalizer sound activated led jump up and down to the music in real time ! Wow this awesome ! Just insert 4 x AAA battery and carry the battery box on your belt clip. So easy so fun, you will be one of the coolest.